A symmetric functions approach to Stockhausen's problem.
A tandem version of the cops and robber game played on products of graphs
In this version of the Cops and Robber game, the cops move in tandems, or pairs, such that they are at distance at most one from each other after every move. The problem is to determine, for a given graph G, the minimum number of tandems sufficient to guarantee a win for the cops. We investigate this game on three graph products, the Cartesian, categorical and strong products.
A technique for computing minors of binary Hadamard matrices and application to the growth problem.
A technique for reconstructing disconnected graphs
A tentative answer to the Castel-San Pietro problem.
A theorem for an axiomatic approach to metric properties of graphs
A theorem of O'Nan for finite linear spaces
A theorem on -connected graphs
A theorem on chains of finite sets, II
A theorem on Hamiltonian line graphs
A Tight Bound on the Set Chromatic Number
We provide a tight bound on the set chromatic number of a graph in terms of its chromatic number. Namely, for all graphs G, we show that χs(G) > ⌈log2 χ(G)⌉ + 1, where χs(G) and χ(G) are the set chromatic number and the chromatic number of G, respectively. This answers in the affirmative a conjecture of Gera, Okamoto, Rasmussen and Zhang.
A topology with order, graph and an enumeration problem.
A tournament result deduced from harems.
A traceability conjecture for oriented graphs.
A transvection decomposition in GL(n,2)
An algorithm is given to decompose an automorphism of a finite vector space over ℤ₂ into a product of transvections. The procedure uses partitions of the indexing set of a redundant base. With respect to tents, i.e. finite ℤ₂-representations generated by a redundant base, this is a decomposition into base changes.
A tree as a finite nonempty set with a binary operation
A (finite) acyclic connected graph is called a tree. Let be a finite nonempty set, and let be the set of all trees with the property that is the vertex set of . We will find a one-to-one correspondence between and the set of all binary operations on which satisfy a certain set of three axioms (stated in this note).
A triangle free configuration
A triple lacunary generating function for Hermite polynomials.
A Triple of Heavy Subgraphs Ensuring Pancyclicity of 2-Connected Graphs
A graph G on n vertices is said to be pancyclic if it contains cycles of all lengths k for k ∈ {3, . . . , n}. A vertex v ∈ V (G) is called super-heavy if the number of its neighbours in G is at least (n+1)/2. For a given graph H we say that G is H-f1-heavy if for every induced subgraph K of G isomorphic to H and every two vertices u, v ∈ V (K), dK(u, v) = 2 implies that at least one of them is super-heavy. For a family of graphs H we say that G is H-f1-heavy, if G is H-f1-heavy for every graph...
A Turán type problem concerning the powers of the degrees of a graph.